- make cert check to accept subjectAltNames, patch from: http://savannah.gnu.org...

Changed files:
    wget-subjectAltNames.patch -> 1.1

diff --git a/wget-subjectAltNames.patch b/wget-subjectAltNames.patch
new file mode 100644 (file)
index 0000000..f8fb55d
--- /dev/null
+++ b/wget-subjectAltNames.patch
@@ -0,0 +1,208 @@
+http://savannah.gnu.org/bugs/?23934
+
+http://savannah.gnu.org/file/wget-1.12-subjectAltNames.diff?file_id=18828
+
+diff --git a/src/openssl.c b/src/openssl.c
+index b55ca8b..b036a3b 100644
+--- a/src/openssl.c
++++ b/src/openssl.c
+@@ -39,7 +39,7 @@ as that of the covered work.  */
+ #include <string.h>
+ 
+ #include <openssl/ssl.h>
+-#include <openssl/x509.h>
++#include <openssl/x509v3.h>
+ #include <openssl/err.h>
+ #include <openssl/rand.h>
+ 
+@@ -486,9 +486,11 @@ bool
+ ssl_check_certificate (int fd, const char *host)
+ {
+   X509 *cert;
++  GENERAL_NAMES *subjectAltNames;
+   char common_name[256];
+   long vresult;
+   bool success = true;
++  bool alt_name_checked = false;
+ 
+   /* If the user has specified --no-check-cert, we still want to warn
+      him about problems with the server's certificate.  */
+@@ -558,10 +560,6 @@ ssl_check_certificate (int fd, const char *host)
+   /* Check that HOST matches the common name in the certificate.
+      #### The following remains to be done:
+ 
+-     - It should use dNSName/ipAddress subjectAltName extensions if
+-       available; according to rfc2818: "If a subjectAltName extension
+-       of type dNSName is present, that MUST be used as the identity."
+-
+      - When matching against common names, it should loop over all
+        common names and choose the most specific one, i.e. the last
+        one, not the first one, which the current code picks.
+@@ -569,51 +567,123 @@ ssl_check_certificate (int fd, const char *host)
+      - Ensure that ASN1 strings from the certificate are encoded as
+        UTF-8 which can be meaningfully compared to HOST.  */
+ 
+-  X509_NAME *xname = X509_get_subject_name(cert);
+-  common_name[0] = '\0';
+-  X509_NAME_get_text_by_NID (xname, NID_commonName, common_name,
+-                             sizeof (common_name));
++  subjectAltNames = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
+ 
+-  if (!pattern_match (common_name, host))
++  if (subjectAltNames)
+     {
+-      logprintf (LOG_NOTQUIET, _("\
+-%s: certificate common name %s doesn't match requested host name %s.\n"),
+-                 severity, quote_n (0, common_name), quote_n (1, host));
+-      success = false;
++      /* Test subject alternative names */
++
++      /* Do we want to check for dNSNAmes or ipAddresses (see RFC 2818)?
++       * Signal it by host_in_octet_string. */
++      ASN1_OCTET_STRING *host_in_octet_string = NULL;
++      host_in_octet_string = a2i_IPADDRESS (host);
++
++      int numaltnames = sk_GENERAL_NAME_num (subjectAltNames);
++      int i;
++      for (i=0; i < numaltnames; i++)
++        {
++          const GENERAL_NAME *name =
++            sk_GENERAL_NAME_value (subjectAltNames, i);
++          if (name)
++            {
++              if (host_in_octet_string)
++                {
++                  if (name->type == GEN_IPADD)
++                    {
++                      /* Check for ipAddress */
++                      /* TODO: Should we convert between IPv4-mapped IPv6
++                       * addresses and IPv4 addresses? */
++                      alt_name_checked = true;
++                      if (!ASN1_STRING_cmp (host_in_octet_string,
++                            name->d.iPAddress))
++                        break;
++                    }
++                }
++              else if (name->type == GEN_DNS)
++                {
++                  /* Check for dNSName */
++                  alt_name_checked = true;
++                  /* dNSName should be IA5String (i.e. ASCII), however who
++                   * does trust CA? Convert it into UTF-8 for sure. */
++                  unsigned char *name_in_utf8 = NULL;
++                  if (0 <= ASN1_STRING_to_UTF8 (&name_in_utf8, name->d.dNSName))
++                    {
++                      /* Compare and check for NULL attack in ASN1_STRING */
++                      if (pattern_match ((char *)name_in_utf8, host) &&
++                            (strlen ((char *)name_in_utf8) ==
++                                ASN1_STRING_length (name->d.dNSName)))
++                        {
++                          OPENSSL_free (name_in_utf8);
++                          break;
++                        }
++                      OPENSSL_free (name_in_utf8);
++                    }
++                }
++            }
++        }
++      sk_GENERAL_NAME_free (subjectAltNames);
++      if (host_in_octet_string)
++        ASN1_OCTET_STRING_free(host_in_octet_string);
++
++      if (alt_name_checked == true && i >= numaltnames)
++        {
++          logprintf (LOG_NOTQUIET,
++              _("%s: no certificate subject alternative name matches\n"
++                "\trequested host name %s.\n"),
++                     severity, quote_n (1, host));
++          success = false;
++        }
+     }
+-  else
++  
++  if (alt_name_checked == false)
+     {
+-      /* We now determine the length of the ASN1 string. If it differs from
+-       * common_name's length, then there is a \0 before the string terminates.
+-       * This can be an instance of a null-prefix attack.
+-       *
+-       * https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike
+-       * */
+-
+-      int i = -1, j;
+-      X509_NAME_ENTRY *xentry;
+-      ASN1_STRING *sdata;
+-
+-      if (xname) {
+-        for (;;)
+-          {
+-            j = X509_NAME_get_index_by_NID (xname, NID_commonName, i);
+-            if (j == -1) break;
+-            i = j;
+-          }
+-      }
++      /* Test commomName */
++      X509_NAME *xname = X509_get_subject_name(cert);
++      common_name[0] = '\0';
++      X509_NAME_get_text_by_NID (xname, NID_commonName, common_name,
++                                 sizeof (common_name));
+ 
+-      xentry = X509_NAME_get_entry(xname,i);
+-      sdata = X509_NAME_ENTRY_get_data(xentry);
+-      if (strlen (common_name) != ASN1_STRING_length (sdata))
++      if (!pattern_match (common_name, host))
+         {
+           logprintf (LOG_NOTQUIET, _("\
+-%s: certificate common name is invalid (contains a NUL character).\n\
+-This may be an indication that the host is not who it claims to be\n\
+-(that is, it is not the real %s).\n"),
+-                     severity, quote (host));
++    %s: certificate common name %s doesn't match requested host name %s.\n"),
++                     severity, quote_n (0, common_name), quote_n (1, host));
+           success = false;
+         }
++      else
++        {
++          /* We now determine the length of the ASN1 string. If it differs from
++           * common_name's length, then there is a \0 before the string terminates.
++           * This can be an instance of a null-prefix attack.
++           *
++           * https://www.blackhat.com/html/bh-usa-09/bh-usa-09-archives.html#Marlinspike
++           * */
++
++          int i = -1, j;
++          X509_NAME_ENTRY *xentry;
++          ASN1_STRING *sdata;
++
++          if (xname) {
++            for (;;)
++              {
++                j = X509_NAME_get_index_by_NID (xname, NID_commonName, i);
++                if (j == -1) break;
++                i = j;
++              }
++          }
++
++          xentry = X509_NAME_get_entry(xname,i);
++          sdata = X509_NAME_ENTRY_get_data(xentry);
++          if (strlen (common_name) != ASN1_STRING_length (sdata))
++            {
++              logprintf (LOG_NOTQUIET, _("\
++    %s: certificate common name is invalid (contains a NUL character).\n\
++    This may be an indication that the host is not who it claims to be\n\
++    (that is, it is not the real %s).\n"),
++                         severity, quote (host));
++              success = false;
++            }
++        }
+     }
+ 
+ 
+@@ -631,3 +701,7 @@ To connect to %s insecurely, use `--no-check-certificate'.\n"),
+   /* Allow --no-check-cert to disable certificate checking. */
+   return opt.check_cert ? success : true;
+ }
++
++/*
++ * vim: tabstop=2 shiftwidth=2 softtabstop=2
++ */